US 20080247375Al

(12) Patent Application Publication (10) Pub. N0.: US 2008/0247375 A1 (19) United States

Muharemovic et al. (43) Pub. Date: Oct. 9, 2008

(54) NETWORK-BASED INTER-CELL POWER Publication Classi?cation CONTROL FOR MULTI-CHANNEL (51) Int Cl WIRELESS NETWORKS H04B 7/208 (2006.01)

H04Q 7/22 (2006.01) (76) Inventors: Tarik Muharemovic, Dallas, TX (52) US. Cl. ....................................... .. 370/344; 455/522

(US); Zukang Shen, Richardson, (57) ABSTRACT TX (US); Pierre Bertrand, Antibes (ER)

Correspondence Address: TEXAS INSTRUMENTS INCORPORATED P 0 BOX 655474, M/S 3999 DALLAS, TX 75265

(21) App1.No.: 12/062,343

(22) Filed: Apr. 3, 2008

Related US. Application Data

(60) Provisional application No. 60/909,900, ?led on Apr. 3, 2007.

500

A method is described for operating a cellular network, where the cellular network uses a plurality of frequency division multiplexing (FDM) bands for wireless communication from user equipment (UE) to a base station (NodeB). At least one band-speci?c cell parameter is computed for at least one the plurality of FDM hands by a serving NodeB. The band speci?c cell parameters are transmitted from the NodeB serv ing a ?rst cell to a NodeB serving a second cell. The band speci?c cell parameters may be computed in response to scheduling information and/ or channel speci?c measure ments made by the NodeB. A UE receives a ?rst Power Con?guration, a Second Power Con?guration, and a Sched uling Message indicative of an FDM band from the set com prising at least from First FDM band and Second FDM band. UE transmits with the First Power Con?guration if the Sched uling Message was indicative of First FDM band, and with the Second Power Con?guration otherwise.

504

l_ —|

l SCHEDULER l

512 513

l MEASURER l l- _|

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l MEASURER l I- _I

PROCESSOR

TRANSCEIVER

UE

520

\ 522

520m 510m

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E E E

522

0 1 1

US 2008/0247375 A1 Oct. 9, 2008 Sheet 1 0f 5

109

FIG. 1

Patent Application Publication

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Patent Application Publication Oct. 9, 2008 Sheet 2 0f 5 US 2008/0247375 A1

50in :- APPLICATIONS 1 :- APPLICATIONS 1 |I-------|| |I-------|| | l SCHEDULER I | | l SCHEDULER l | |'—— ————'| |'—— ————'| l l l l : 512 513 : : 512“ 513n : l | MEASURER l l l l MEASURER | l l|_______|l l|_______|l L___ ____J L____ ___J

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Patent Application Publication Oct. 9, 2008 Sheet 3 0f 5 US 2008/0247375 A1

I' _ _ _ _ _ _ _ _ _ __‘l

RF <—| POWER |

11 T T 11 : CONFIGURATION : 602\ BASEBAND SIGNAL : FIRST POWER :

M 1 k“ | CONFIGURATION V610 l

CHANNELIZER : 6L2 811 : 606\ BASEBAND SIGNAL : SECOND POWER :

GENERATOR : CONFIGURATION :

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600/ MODULATED SYMBOLS FIG- 6

791 792 703 704 705 706 707 708 709 710 711 712 713 714 715 716

717

718

719

720

721

722 M

723 FREQ

724

700 FIG. 7

Patent Application Publication

I

Oct. 9, 2008 Sheet 4 0f 5

COMPUTE AT LEAST ONE BAND-SPECIFIC CELL PARAMETER FOR AT LEAST ONE

OF A PLURALITY OF FDM BANDS

I TRANSMIT THE BAND-SPECIFIC CELL

PARAMETER FROM A NODEB SERVING A FIRST CELL TO A NODEB SERVING A SECOND CELL

I

806/ RECEIVE ANOTHER BAND-SPECIFIC

CELL PARAMETER FROM THE NODEB SERVING THE SECOND CELL

I

808/ ADJUST USE OF AT LEAST ONE OF THE

PLURALITY OF FDM BANDS IN RESPONSE TO THE RECEIVED PARAMETER

FIG. 8

I COMPUTE AT LEAST ONE BAND-SPECIFIC CELL PARAMETER FOR AT LEAST ONE

OF A PLURALITY OF FDM BANDS

I TRANSMIT THE BAND-SPECIFIC CELL

PARAMETER FROM A NODEB SERVING A FIRST CELL TO A NODEB SERVING A SECOND CELL

I RECEIVE ANOTHER BAND-SPECIFIC

CELL PARAMETER FROM THE NODEB SERVING THE SECOND CELL

I

808/ ADJUST USE OF AT LEAST ONE OF THE

PLURALITY OF FDM BANDS IN RESPONSE TO THE RECEIVED PARAMETER

I 910/

RECEIVING TWO OR MORE BAND SPECIFIC POWER CONFIGURATIONS AT A UE

I

912/ OPERATING THE UE IN RESPONSE TO

SCHEDULED BAND AND BAND-SPECIFIC POWER CONFIGURATIONS

FIG. 9

US 2008/0247375 A1

US 2008/0247375 A1

NETWORK-BASED INTER-CELL POWER CONTROL FOR MULTI-CHANNEL

WIRELESS NETWORKS

CLAIM OF PRIORITY UNDER 35 U.S.C. ll9(e)

[0001] The present Application for Patent claims priority to US. Provisional Application No. 60/909,900 entitled “Net Work-Based Inter-Cell PoWer Control For Multi-Channel Wireless Networks” ?led Apr. 3, 2007, incorporated by ref erence herein.

FIELD OF THE INVENTION

[0002] This invention generally relates to cellular commu nication systems, and in particular to Wireless frequency divi sion multiplexed operation.

BACKGROUND OF THE INVENTION

[0003] Wireless cellular communication netWorks incorpo rate a number of mobile UEs and a number of NodeBs. A NodeB is generally a ?xed station, and may also be called a base transceiver system (BTS), an access point (AP), a base station (BS), or some other equivalent terminology. As improvements of netWorks are made, the NodeB functional ity evolves, so a NodeB is sometimes also referred to as an evolved NodeB (eNB). In general, NodeB hardWare, When deployed, is ?xed and stationary, While the UE hardWare is portable. [0004] In contrast to NodeB, the mobile UE can comprise portable hardWare. User equipment (UE), also commonly referred to as terminal or mobile station, may be ?xed or mobile device and may be a Wireless device, a cellular phone, a personal digital assistant (PDA), a Wireless modem card, and so on. Uplink communication (UL) refers to a commu nication betWeen the mobile UE and the NodeB, Whereas doWnlink (DL) refers to communication from the NodeB to the mobile UE. Each NodeB contains radio frequency trans mitter(s) and the receiver(s) used to communicate directly With the mobiles, Which move freely around it. Similarly, each mobile UE contains radio frequency transmitter(s) and the receiver(s) used to communicate directly With the NodeB. In cellular netWorks, the mobiles cannot communicate directly With each other but have to communicate With the NodeB. Embodiments of the invention, hoWever, can be applied even beyond such cellular netWorks, since only con cepts of Wireless transmission and reception are needed. Nev er‘theless, the present invention Will be described in the con text of a cellular network.

[0005] Orthogonal Frequency Division Multiple Access (OFDMA) is a multi-user version of the popular Orthogonal Frequency-Division Multiplexing (OFDM) digital modula tion scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This alloWs simultaneous transmission from several users. Based on feedback information about the channel conditions, adap tive user-to-subcarrier assignment can be achieved. If the assignment is done suf?ciently fast, this further improves the OFDM robustness to fast fading and narroW-band co-channel interference, and makes it possible to achieve even better system spectral ef?ciency. Different number of sub-carriers can be assigned to different users, in vieW to support differ entiated Quality of Service (QoS), i.e. to control the data rate and error probability individually for each user. OFDMA is used in the mobility mode of IEEE 802.16 WirelessMAN Air

Oct. 9, 2008

Interface standard, commonly referred to as WiMAX. OFDMA is currently a Working assumption in 3GPP Long Term Evolution doWnlink, named High Speed OFDM Packet Access (HSOPA). Also, OFDMA is the candidate access method for the IEEE 802.22 “Wireless Regional Area Net Works”. [0006] NodeB is a term used in UMTS to denote the BTS (base transceiver station). In contrast With GSM base stations, NodeB uses WCDMA or OFDMA as air transport technol ogy, depending on the type of netWork. As in all cellular systems, such as UMTS and GSM, NodeB contains radio frequency transmitter(s) and the receiver(s) used to commu nicate directly With the mobiles, Which move freely around it. In this type of cellular netWorks the mobiles cannot commu nicate directly With each other but have to communicate With the BTSs

[0007] A NodeB can serve several cells, also called sectors, depending on the con?guration and type of antenna. Possible con?gurations include omni cell (3 60°), 3 sectors (3><l20°) or 6 sectors (3 sectors 1200 Wide overlapping With 3 sectors of different frequency). [0008] The signals from different users Within the same cell interfere With one another. This type of interference is knoWn as the intra-cell interference. In addition, the base station also receives the interference from the users transmitting in neigh boring cells. This is knoWn as the inter-cell interference

[0009] Control information bits are transmitted, for example (in PUCCH), in the uplink (UL), for several pur poses. For instance, DoWnlink Hybrid Automatic Repeat ReQuest (HARQ) requires at least one bit of ACK/NACK transmitted information in the uplink, indicating successful or failed circular redundancy check(s) (CRC). Furthermore, an indicator of doWnlink channel (CQI) needs to be transmit ted in the uplink to support mobile UE scheduling in the doWnlink. While CQI may be transmitted based on a periodic or triggered mechanism, the ACK/NACK needs to be trans mitted in a timely manner to support the HARQ operation. Note that ACK/NACK is sometimes denoted as ACKNAK or just simply ACK, or any other equivalent term. This uplink control information is typically transmitted using the physical uplink control channel (PUCCH), as de?ned by the 3GPP Working groups (WG), for evolved universal terrestrial radio access (EUTRA). The EUTRA is sometimes also referred to as 3GPP long-term evolution (3GPP LTE). For said reasons, structure of the PUCCH provides for suf?ciently high trans mission reliability. [0010] In addition to PUCCH, the EUTRA standard also de?nes a physical uplink shared channel (PUSCH), intended for transmission of uplink user data. The Physical Uplink Shared Channel (PUSCH) can be dynamically scheduled. This means that time-frequency resources of PUSCH are re-allocated every sub-frame. This (re)allocation is commu nicated to the mobile UE using the Physical DoWnlink Con trol Channel (PDCCH). Alternatively, resources of the PUSCH can be allocated semi-statically, via the mechanism of persistent scheduling. Thus, any given time-frequency PUSCH resource can possibly be used by any mobile UE, depending on the scheduler allocation. Physical Uplink Con trol Channel (PUCCH) is different than the PUSCH, and the PUCCH is used for transmission of uplink control informa tion (UCI). Frequency resources Which are allocated for PUCCH are found at the tWo extreme edges of the uplink frequency spectrum. In contrast, frequency resources Which are used for PUSCH are in betWeen. Since PUSCH is

US 2008/0247375 A1

designed for transmission of user data, re-transmissions are possible, and PUSCH is expected to be generally scheduled With less stand-alone sub-frame reliability than PUCCH.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Particular embodiments in accordance With the invention Will noW be described, by Way of example only, and With reference to the accompanying drawings: [0012] FIG. 1 is a representation of tWo cells in a cellular communication netWork that includes an embodiment of FDM band-speci?c information exchange; [0013] FIGS. 2-4 illustrate various exemplary Ways of par titioning system bandWidth into at least tWo FDM bands; [0014] FIG. 5 is a block diagram of a UE and multiple interconnected base stations in the netWork of FIG. 1; [0015] FIG. 6 is a block diagram of a UE transmitter in accordance With an embodiment of the invention; [0016] FIG. 7 is a time vs frequency plot illustrating an uplink sub-frame With several representative resource blocks used for frequency division multiplexing (FDM) for Wireless communication in the netWork of FIG. 1; [0017] FIG. 8 is a How diagram illustrating derivation of FDM band-speci?c cell parameters used in the netWork of FIG. 1; [0018] FIG. 9 is a How diagram illustrating use of FDM band-speci?c cell parameters in the netWork of FIG. 1; and [0019] FIG. 10 is a block diagram ofa mobile user device for use in the netWork of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0020] Conventional cell control mechanisms do not employ frequency division multiplexing (FDM) band-spe ci?c direct information exchange betWeen NodeBs serving different cellular sites. Thus, conventional cell control mechanisms are unable to optimally control and deal With frequency-selective interference Which individual UE gener ates to neighboring cell sites. This feature becomes especially important for any kind of frequency division multiplexing (FDM) access strategies. In contrast, embodiments of the cell control method described herein alloW an effective control of inter-cell interference by employing frequency division mul tiplexing (FDM) band-speci?c information exchange betWeen NodeBs serving different cellular sites. Conse quently, in some embodiments of the invention, UEs Which transmit on a speci?c frequency band can transmit With dif ferent poWer con?gurations, When compared to UEs Which use a different frequency band. In other embodiments, band speci?c scheduling information is exchanged betWeen NodeBs Which control different cells. Scheduling informa tionpertains for future transmissions. Consequently, a NodeB can receive an advanced Warning before an FDM band-spe ci?c interference occurs. Thus, the NodeB can either re-adjust its oWn scheduling decision to avoid interference, or alterna tively, it can adapt the transmit poWer and/or modulation and/or coding of scheduled serving UEs, to minimize the impact of impending interference. Thus, the present cell con trol method can achieve much better overall system spectral ef?ciency than the conventional control method. In some embodiments, a level of interference generated at some spe ci?c FDM bands is monitored by the neighboring cell sites (e. g. non-serving NodeBs), upon Which a frequency speci?c indicator is communicated to the serving cell (i.e. serving

Oct. 9, 2008

NodeB, speci?cally) of the UE. In other embodiments, pre dictive scheduling of frequency bands can be performed so that UE near an edge of one cell are scheduled to use different frequency bands from nearby UE in a neighboring cell. [0021] FIG. 1 shoWs an exemplary Wireless telecommuni cations netWork. The illustrative telecommunications net Work includes representative NodeBs 101, 102, Which are also referred to as base-stations. In this representation only tWo cells 101, 102 are illustrated for simplicity, but it should be understood that a typical netWork includes a large matrix of cells and each cell is generally completely surrounded by neighboring cells. Each of NodeBs 101 and 102 are operable over corresponding cells 111 and 110, respectively. HoWever, it should be understood that a typical NodeB can serve mul tiple cells. Handset or other UE 103 is shoWn in cell 111, Which is served by the NodeB 101. NodeB 101 is transmitting to and receiving transmissions from UE 103. Uplink radio transmissions from 103 to 101 are shoWn as 107, Whereas doWnlink radio transmissions are 112. Interference to link 107 is generated by 104 through the radio channel 106. Simi larly, UE 103 also generates interference via radio channel 105. As discussed above, in some embodiments, FDM band speci?c parameters may be provided such that UE 103 trans mits With different poWer con?gurations depending on Which FDM band it is using at any given time. To this goal, note that FIG. 2 shoWs the entire system bandWidth 200, partitioned into at least tWo FDM bands, namely FDM band 201 and FDM band 202. Note that the system bandWidth partition doesn’t have to be contiguous. To illustrate this, FIG. 3 shoWs a system bandWidth 300 divided into at least tWo FDM bands 301 and 302. Similarly, FIG. 4 shoWs system bandWidth 400 divided into at least tWo FDM bands 401 and 402. Backhaul link 109 betWeen NodeB 101 and NodeB 102 is also shoWn in FIG. 1. In some embodiments, the backhaul 109 link serves for exchange of FDM band-speci?c cell parameters. [0022] The UE equipment 103 is currently in cell 111 and is being served by NobeB 101. Cell 110 can be a neighbor cell and the NodeB 102 is not serving UE 103; hoWever, NobeB 102 is serving UE 104 as represented by respective transmis sion 108. It is to be understood that typically each cell Will contain doZens or hundreds of UE, but the operation of each Will be the same as described herein. In this embodiment of band-speci?c cell parameters, each NodeB 101, 102 derives a set of FDM band-speci?c cell parameters for at least one of the FDM bands that are being used Within the respective cell. As part of this derivation process, NodeB 101, for example, may also monitor transmissions from UE in neighboring cells, such as UE 104, as illustrated by respective represen tative interference link 106. In a similar manner, NodeB 102 Will derive a set of FDM band-speci?c cell parameters by monitoring signals from served UE Within their respective served cells and also by monitoring (interfering) signals from non-served UEs in neighboring cells.

[0023] In some embodiments, FDM band-speci?c informa tion exchange betWeen NodeBs is performed using the back haul netWork. The backhaul netWork is, in some embodi ments, the backbone netWork. In other embodiments, the backhaul netWork is achieved by direct links betWeen NodeBs serving near-by cells. Unlike in the radio netWork controller (RNC)ibased netWork, information Which is communicated from one NodeB is not processed by the net Work. Rather, in some embodiments of the present invention, the netWork only attempts the delivery of the exact sent infor mation, from one NodeB to another. Consequently, no radio

US 2008/0247375 A1

network controller (RNC) is required. In some embodiments, the backhaul netWork can be alliIP network, or the internet. Timely delivery of the frequency band-speci?c information is preferred, and thus, delivery latencies can be of concern. Consequently, a high quality of service (QOS) parameters can be aWarded to the FDM band-speci?c information Which is exchanged betWeen NodeBs. In other embodiments, the FDM band-speci?c information exchange from one NodeB to another can occur through a UE.

[0024] A serving cell site is de?ned as the cell site Which controls the transmission of a UE. Each cell site is controlled by a NodeB. HoWever, one NodeB can control multiple cell sites. Consequently, Within a cell a UE is said to be a served UE and the NodeB is the serving NodeB of that cell site. A non-serving cell site of a UE is de?ned to be a cell site that does not directly control the transmission of the UE. More over, closed loop poWer control is de?ned as a poWer control mechanism in Which explicit poWer control commands are issued from a serving cell site to its serving UEs to control their transmission poWer levels. Closed-loop poWer control command can sometimes be regarded as an absolute directive on poWer settings on the UE. HoWever, in the literature, the term closed-loop typically refers to a differential poWer con trol (sending poWer changes With respect to previous poWer settings). Open loop poWer control schemes adjust the poWer control parameters at either a cell site or UE, Without explicit poWer control commands from a serving cell site to its serving UEs.

[0025] For OFDMA based systems, including Single Car rier Orthogonal Frequency Division Multiple Access (SC OFDMA), including Discrete Fourier Transform (DFT) spread OFDMA, channels can be distinct sub-carrier sets, also called resource blocks (RB). Alternatively, channels can be collections of RBs. For CDMA based systems, channels can be sets of access signature codes. Thus, reference herein to frequency division multiplexing (FDM) bands Will be understood to refer to either one resource block (RB), or a collection of resource blocks. For example, in different embodiments, a notion of an FDM band could range from one to 100 resource blocks (RBs). In the 3GPP EUTRA Wireless standard, a siZe of the resource block (RB) has been adopted to be 180 kHZ, Which is also a granularity at Which FDM bands canbe allocated to UEs. The choice of l 80 kHZ RB Will optimiZe the system performance, even When applied in con junction With FDM band-speci?c information exchange. Consequently, in some embodiments of the invention, and FDM band is an integral multiple of a resource block (RB), Which is an integral multiple of 180 kHZ. Such choice of an FDM band is important since, With typical channels being deployed, the coherence bandWidth is approximately 180 kHZ. Consequently, interference statistics, incurred at adja cent NodeBs, Will stay approximately constant across the resource block (RB). HoWever, to reduce signaling overhead, an FDM band can be understood to be a collection of resource blocks. Furthermore, since embodiments of the invention refer to a plurality of FDM bands, different FDM bands can have different siZes. For instance, a ?rst FDM band can be substantially narroWer than the second FDM band. In other embodiments, siZes of FDM bands can be substantially simi lar. Each FDM band need not be contiguous in nature. Rather, it can be composed of pieces of spectrum. [0026] Band-speci?c information exchange occurs betWeen NodeBs. Band-speci?c information exchange can be in reference to future activity or in reference to past activ

Oct. 9, 2008

ity. In some embodiments, band-speci?c information exchange is in reference to past activity. In these embodi ments, a NodeB typically performs band-speci?c measure ments, processes them, and exchanges them With other NodeBs through the backhaul netWork. In other embodi ments, band-speci?c information exchange is in reference to future activity. In such embodiments, FDM band-speci?c scheduling information (Which Will be applied at the UE in future sub-frames) is exchanged betWeen NodeBs through the back-haul netWork. HoWever, it is not precluded that a NodeB communicates both past and/or future scheduling decisions and past measurements through the back-bone net Work.

[0027] In some embodiments of the invention, a NodeB derives FDM band-speci?c parameters as folloWs. First a NodeB performs at least one measurement on the FDM band. This measurement can be a measurement of any of the fol loWing (or a combination thereof): received signal poWer, interference poWer, thermal noise poWer, signal to interfer ence poWer ratio (SIR), signal to interference and noise poWer ratio (SINR), throughput measurement, throughput measure ment for a group of UEs (e. g. cell-edge throughput), handover measurement, handover indicator measurement, signal rise over thermal (signal RoT), interference rise-over thermal (in terference RoT), signal and interference rise over thermal (signal and interference RoT), or any other measurements NodeB measurement de?ned by the standard being deployed. Thus, in some embodiments of the invention, an FDM band speci?c RoT measurement is made. This measurement is then processed, for instance, quantiZed, compared With some pre de?ned value, or other. In some embodiments, if the mea sured RoT exceeds a speci?c pre-de?ned value, a FDM band speci?c overload indication is sent to at least one (presumably adjacent) NodeB, Which serves an adjacent cell. In this embodiment, the FDM-speci?c overload indication refers to the FDM band that the measurements are performed on. Thus, in order to derive at least one band-speci?c cell parameter, each cell’s serving base station (N odeB) monitors parameters on each channel (FDM channel), Which can include one or more of the folloWing: signal poWer, interference poWer, channel throughput and/or performance, cell-edge through put and/or performance, cell-load and/or number of users in the scheduler range, any other channel parameter that is cur rently monitored on a cell basis or may be later found to be useful.

[0028] NoW, in contrast, We focus on a NodeB Which receives the band-speci?c parameter (or more parameters). The receiving NodeB can undertake actions to adjust trans missions of its UEs, in accordance to the value of the param eter. For example, in some embodiments of the invention a received parameter is a band-speci?c overload indication. Suppose that the overload indication Was indicative of exces sive interference in an adjacent cell. In some embodiments, the receiving NodeB stops scheduling UEs on the associated FDM band for a certain period of time (if e. g. overload indi cation Was overly excessive). Thus, interference to adjacent cells is reduced. In other embodiments, the receiving NodeB undertakes actions to reduce transmission poWer for UEs Which are transmitting on the associated band, Where the overload indicator has signaled e.g. moderately excessive interference. Thus, in some embodiments, the NodeB Which receives e.g. moderately excessive interference indication sends a poWer-doWn (by x dB for example) command to UEs transmitting on the associated FDM band. This poWer doWn

US 2008/0247375 A1

command can be UE-speci?c. However, in some embodi ments, the poWer-doWn command can be FDM band- speci?c, and thus a UE Which happens to be scheduled on the associ ated FDM band reduces power. In such embodiments, a scheduling decision (Which FDM band) also affects transmis sion poWer. In such embodiments, poWer control commands can be speci?c to a group of UEs, Where the group is de?ned as those UEs Which are scheduled on the associated FDM band. Such signaling can reduce doWnlink overhead.

[0029] In other embodiments, the NodeB Which receives an excessive FDM band-speci?c interference indication can undertake more subtle actions to reduce interference to adja cent cells. For example, in some embodiments, poWer settings of the UE are also controlled through radio resource con?g ured (RRC) poWer-control parameters. These RRC param eters are typically signaled through higher layers. Thus, in some embodiments, the RRC poWer con?guration of a UE is FDM-band speci?c. In some embodiments, the RRC poWer con?guration can even have different parameters, depending on the FDM band. Thus, in some embodiments, the NodeB signals at least tWo poWer con?gurations for a UE. First poWer con?guration is valid for a ?rst FDM band, and a second poWer con?guration is valid for a second FDM band. The UE poWer is then determined once the UE also receives an actual scheduling message. If the scheduling message is indicative of the ?rst FDM band, ?rst poWer con?guration is applied, and if the scheduling message is indicative of the second FDM band, the secondpoWer con?guration is applied. [0030] Thus, in some embodiments poWer control adjust ments are FDM band-speci?c. For example, a particular UE can receive x dB reference poWer up command on ?rst FDM band, and y dB reference poWer doWn on second FDM band. Thus, When, in present or in future, the said UE is scheduled on ?rst FDM band, it applies a different transmit poWer from When it is scheduled on the second FDM band. There can be tWo different kinds of FDM band-speci?c poWer control com mands: (a) poWer control command Which adjusts a reference poWer, Which becomes relevant (i.e. applied) only When the UE becomes scheduled on a corresponding FDM band, and (b) the poWer control command Which is associated With the scheduling grant, and expires after. Upon, expiration, the reference poWer on the FDM band is maintained as before. Same principle can be applied for both absolute and differ ential poWer control commands. In other embodiments, a given differential poWer control command can be FDM band speci?c. For example, if a UE receives an “up” poWer com mand, this can be interpreted as up by x dB if the UE is scheduled on ?rst FDM band, and up by y dB is the UE is scheduled on second FDM band.

[0031] Each cell’s serving NodeB processes the measured parameter(s). This processing can be on a per-channel basis, or on a per-collection of channels basis. This processing can be either quantization, or it can be further processing Which alloWs a cell to make inferences about its parameters or about adjacent cells parameters. Processed parameters, or infer ences thereabout, are then forWarded or broadcast to other cells in the netWork, on a per-channel basis, or on a per collection of channels basis. Typically, the set of band speci?c cell parameters Will be forWarded to adjacent, neighboring cells’ NodeBs. HoWever, depending on cell topography they may also be forWarded to more remote cells. In some embodi ments, sets of band speci?c cell parameters from many dif ferent cells may be transferred to a central coordinating sys tem that coordinates the scheduling and control of a large

Oct. 9, 2008

number of cells. In some embodiments, FDM band-speci?c poWer adjustments mean that both the serving cell and a particular UE maintain a distinct reference transmit poWer for each FDM band. Thus, Whenever a UE is scheduled on a particular FDM band, the UE transmits With the band- speci?c reference poWer. If additional poWer corrections are applied With the scheduling grant, then the UE incorporates the poWer corrections into the transmit poWer settings together With the reference poWer.

[0032] Thus, as a simple example of the embodiment, in OFDMA based systems, each cell can monitor interference in groups of RBs or even on an individual RB basis. If this

interference exceeds a threshold, then per-group or per-RB overload indicator is sent or broadcasted to adjacent cells. This Would be an example of frequency selective overload indicator, sent over the netWork backhaul. On the ?ip side, each cell receives processed parameters from adjacent cells, on a per-channel (FDM band) basis. Then, each cell’s NodeB combines these processed parameters With its oWn measure ments and uplink signaled parameters. From these combina tions, the NodeB may do one or more of the folloWing: (a) Issue per-UE speci?c, per FDM band-speci?c, poWer spectral density adjustments, (b) Adjust (FDM band-speci?c) param eters of the open-loop poWer control, or (c) select FDM band speci?c scheduling allocations to avoid current or future con ?ict With FDM band-usage in nearby cells. [0033] Band-speci?c poWer adjustments in actual trans mission from a UE only apply to the UE When the UE is scheduled on that particular channel. Thus, if the UE is not scheduled on a particular channel, the poWer density adjust ments are just used for future reference. Then, Whenever the UE becomes scheduled on a particular channel, the transmit poWer for that particular channel, Which is inferred from band-speci?c poWer density commands received from the serving NodeB, is already determined. [0034] As an example of the embodiment, We consider a scenario Where the poWer control equation is P[k] :min{PMAX, l0 log1O(M[k])+PO+0t PL+ATF[k]+g[k]}, Where the said poWer control equation is calculated at the UE. The above equation is in the dBm scale. In the above equation, M[k] is the number of resource blocks that the transmission has been scheduled on, at sub-frame k. Also, the P MAXis the maximum transmission poWer at the UE, Which is pre-de?ned based on the UE poWer class. Parameter PL is the doWnlink path loss estimated at the UE (or alternatively at the NodeB). Parameter ATF[k] is the poWer increase or reduction due to the modulation and coding adjustment (sometimes referred to as the TFItransport format), Which is thus dependent on the choice of channel code rate and modulation. The g[k]:g[k— l]+6 is a differential poWer accumulation. Finally, the value P0 is a nominal component, Which can be either broadcasted to UEs or informed using RRC signaling. The set of said param eters (PO, 0t, ATF[k], g[k]) can be called a UE poWer con?gu ration. Note that a UE poWer con?guration exists even When the UE is silent, because these parameters are maintained in the memory of the UE. Transmission poWer is applied only When the UE is actually scheduled. As an example of the embodiment, a number of the above parameters can be FDM band-speci?c. In one embodiment of the invention the param eter 0t is FDM band-speci?c. Thus, a ?rst FDM band can have a different value of a than the second FDM band. Further more, either one of these values can be ?xed (such as (F1), and non-con?gurable, or both can be con?gured. In another embodiment of the invention, the nominal value PO is also

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band-speci?c. Thus, here, ?rst FDM band can have (?rst) either ?xed or doWnlink (DL) signaled value of PO, all the While second FDM band has (second) either ?xed or doWn link (DL) signaled value of P0. In another embodiment of the invention, the ATF[k] is differently con?gured for different FDM bands. For example, a ?rst FDM band has a ?rst con ?guration for ATF[k] While the second FDM band has a sec ond con?guration of ATF[k]. In another embodiment of the invention, differential poWer accumulation g[k] is differently computed for ?rst FDM band and second FDM band, for example, g[k]:g[k—l]+6, Where 6 can be differently con?g ured for the ?rst and the second FDM band. In one embodi ment, physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH) are transmitted on tWo separate FDM bands. For example, ?rst FDM band is PUSCH and second FDM band is PUCCH. The set of said parameters (PO, 0t, ATF[k], g[k]) can be called a UE poWer con?guration (for sub-frame k), With potentially some other parameters being present, in some embodiments. In other embodiments, a reduced or alternate set of parameters can be used (for example, (PO, 0t, 6) as a poWer con?guration). Note that the UE poWer con?guration is signaled, and is not utiliZed by the UE until the UE is actually scheduled. Only once the UE is scheduled, the con?guration is applied. Thus, in some embodiments, the set of parameters (PO, 0t, ATF[k], g[k]) is FDM band-speci?c, and thus, different poWer settings are applied depending on Whether the UE is scheduled on the ?rst FDM band or on the second FDM band. In essence, there can exist tWo sets of poWer con?gurations, like (PO, 0t, ATF[k], g[k])FDMl Which is the ?rst con?guration and a (PO, 0t, ATF[k], g[k])FDM2 Which is a second con?guration. Note that some elements of poWer con?guration can be updated using DL signaling (poWer con?guration message), While others can be simply ?xed. Thus, in some embodiments of the invention, a poWer con?guration message is any message Which updates values for the elements of the set (PO, 0t, ATF[k], g[k]). Such message or messages can be achieved through signaling in physical doWnlink control channel (PDCCH), or through RRC signaling, Which can be done through physical doWn link shared channel (PDSCH). In other embodiments, ele ments of poWer con?guration can be added and maintained as a reference poWer con?guration (possibly including a 6)). [0035] In other embodiments of the invention, FDM band speci?c parameters are shared through the back-haul net Work, Where the parameters are computed using information produced by the scheduler of the NodeB. Usually, informa tion produced by the scheduler of the NodeB pertains for future transmissions, Which is the case in some embodiments. In other embodiments, scheduling information for previous transmissions can be used. Scheduling information incorpo rates identity of a UE, together With an FDM band (or a sub-band, i.e. part of the FDM band) that the UE has been scheduled on, together With the choice of modulation to be used, together With the choice of channel coding scheme to be used, together With a schedule duration. Elements of the enumerated list are produced by the scheduler, Where the scheduler can also produce additional information, in some embodiments. Thus, in some embodiments, the scheduler belonging to a NodeB produces scheduling information. This scheduling information can then be processed, in some embodiments. This processing can be, for instance, simple extraction of the elements of scheduling information. Other, more complicated processing is not precluded. In some embodiments, a NodeB looks up if a cell-edge UE has been

Oct. 9, 2008

scheduled, and if so, it sends an advanced Warning to another NodeB, through a backhaul netWork. This advanced Warning can also include the FDM band Where the cell edge UE has been scheduled, together With additional information. In some embodiments, the receiving NodeB can then choose to avoid scheduling another cell-edge UE on the said FDM band. Note that a ping-pong effect can occur, Where NodeBs keep changing the schedule, Which in turn keeps colliding. In some embodiments, this is resolved by a-synchronicity, Where different NodeBs send their processed scheduling information through the backhaul netWork at different times.

[0036] In other embodiments of the invention, a number of UEs Which is scheduled for future transmissions can be shared as FDM band-speci?c information. For example, if more that one UE is scheduled in future on a particular FDM band (by a ?rst NodeB), an indicator can be sent to a second NodeB that UL virtual-MIMO (multiple input-multiple out put) transmission is to be used, Which Will create more inter ference to that FDM band. Consequently, the second NodeB can attempt to adapt the parameters of its oWn transmission in order to either avoid interference or to mitigate it.

[0037] In other embodiments of the invention, the identity of the UE Which is scheduled for transmission in a future sub-frame, on a particular FDM band, is communicated via the backhaul netWork, from the ?rst NodeB to the second (non-serving) NodeB. The second NodeB, can thus, based on its oWn prior measurements, and knoWledge of Which inter fering UE is to be scheduled, adapt parameters of transmis sion for its serving UEs. In some embodiments of the inven tion, a simple intent to interfere on a particular FDM band is communicated from ?rst NodeB to a second NodeB. The second NodeB is then informed about impending interfer ence, and thus, it can adapt parameters of transmission for its serving UEs. In some embodiments, the second NodeB sim ply reduces the modulation order for UEs Which are to be scheduled on the FDM band. In other embodiments, the sec ond NodeB increases the channel coding rate for UEs Which are to be scheduled on the FDM band. Thus, interference prediction is achieved, and system throughput can be improved. In some embodiments, the ?rst NodeB is alloWed to send an update of the intent to interfere on a particular FDM band, during a particular sub-frame. In such cases, the second NodeB can consider only the intent mes sage Which arrives the last (i.e. any prior message for a particular sub-frame and FDM band is over-ridden). In other embodiments, all mes sages about the intent to interfere are combined.

[0038] FIG. 7 is an illustrative format of an UL sub-frame 700 for use in the netWork of FIG. 1. Elements of the present invention Will be described in the context of EUTRA sub frame 700, even though its applicability is broader. FIG. 7 describes transmission of EUTRA sub-frame 700 comprising tWo slots 701 and 702. Duration of the EUTRA sub-frame is 1 ms, Which means that duration of tWo slots 701 and 702 is 0.5 ms each. Each slot comprises 7 symbols. For example, slot 701 comprises symbols 703, 704, 705, 706, 707, 708, 709. The slot 702 comprises symbols 710, 711, 712, 713, 714, 715, 716. Demodulation Reference Symbols (DM RS) are sent in 706 and 713, and are used to derive channel estimates Which are needed for coherent demodulation of the remaining Symbols. Furthermore, Demodulation Reference Symbols, as received, can be used to compute estimates of interference, as common in prior art. In addition to 706 and 713, there may be, at times other RS, Which are the sounding reference sym bol (RS). Sounding RS can be con?gured by the NodeB.

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Position of the sounding RS is debated. Each symbol has a time duration equal to approximately T, Which is a function of the slot time. In this embodiment, the slot time is 500 usec. Since the ?rst symbol in the slot has more cyclic pre?x samples, not all symbols are exactly equal in duration, as per TS36.21 1. Nevertheless, all symbols can be considered to be approximately equal in duration, Which doesn’t exceed 75 usec. Note that if all symbols Were exactly equal in duration, the symbol time T Would approximately be equal to 500 usec/7:7l.4 usec. FIG. 7 also illustrates several resource blocks (RBs), namely RBs 717-724. An FDM band can com prise one or more resource blocks. Note that this plot illus trates only 8 RBs, but it should be understood that many more RBs can be used in a typical netWork deployment. Time-Wise, each transmission is performed as a series of symbols for the duration 700. Typically a Wideband sounding reference signal (SRS) can be transmitted With each sub-frame that can be used by the NodeB for poWer, signal quality and timing variation measurement purposes. In such cases, the SRS can be applied to a group of RBs, and the transmission of the SRS can be Wide-band When compared With other transmissions from the UE Which transmits SRS. Also, Within each frame there are typically one or more narroW band demodulation

reference signals (DMRS), sent for the duration 706 and 713, Which can be used to determine individual channel poWer and interference levels. When a particular UE receives a grant to transmit, it transmits one or more a sub -frames on a particular group of RBs that is allocated by the scheduler in the serving NodeB. The scheduler may also allocate a single RB, or if the UE has a lot of data to transfer it may be allocated several or many more RBs to use in parallel, depending on tra?ic loads from other UE Within the cell. Over time, a given UE may be allocated a particular RB or group of RBs, and then later by allocated a different RB or group of RBs. In some embodi ments of the invention, an FDM band is a speci?c group of RBs, Which can be pre-determined. For example, PUCCH comprises tWo or more RBs from the tWo edges of the system spectrum, While the PUSCH is in the interior of the system spectrum. In some embodiments, PUCCH and PUSCH are the tWo different FDM bands (?rst and second, or second and ?rst). In one embodiment, measurements based on the Wide band SRS may be used to derive FDM band-speci?c cell parameter(s) that apply to a group of RBs that are covered by the SRS. In another embodiment, measurements based on the narroW band DMRS may be used to derive FDM band-spe ci?c parameters that apply to an individual RB. In this embodiment, each individual RB has a bandWidth of 180 kHZ. In 3gpp EUTRA, a RB, Which is a resource block, comprises 12 sub-carriers (i.e. tones). [0039] FIG. 6 is a block diagram Which illustrates a UE transmission in accordance With an embodiment of the inven tion. In FIG. 6. channeliZer 601 can be used to form symbols of the sub-frame in FIG. 7. The channeliZer of FIG. 6 begins With complex modulated samples, Which can belong to a constellation such as BPSK, QPSK, 8-PSK, l6 QAM, 64 QAM or some other constellations. This hoWever, is not man datory. Modulated Symbols 600 can be transformed by the Transform Pre-Coder 603. One example of the Transform Pre-Coder 203 is Z[k]:[3 Zl- d[i]exp(—j2s'cki/L), Where sum 2, extends across all indexes “i” in {0,1, . . . , L-l }, Where “j” is the complex unit, Where at is the Well-known constant (ap proximately 3.14), Where d[i] are symbols of the sequence 600 Which enters the Transform Pre-Coder 603, Where “L” is the length of both the sequence Which enters (600) and the

Oct. 9, 2008

sequence Which is outputted (604) by the Transform Pre Coder 603, Where [3 is a normalization constant (e.g. inverse square root of L). Note the “L” can be the number of tones allocated on PUSCH, for this particular mobile UE. In some embodiments, the Transform Pre-Coder 603 can be imple mented using a Discrete Fourier Transform (DFT). Transform Pre-Coder 603 is coupled to the Resource Map 605, Which describes the set of tones Which are allocated to the UE for the present sub-frame. Resource Map 605 is coupled With the Baseband Signal Generator 606. Thus, the Resource Map 605 maps said samples Z[k] onto a[m], Which is the input to the Baseband Signal Generator. Thus, in some embodiments, sequence of a[m] contains samples of the sequence Z[k], along With some other possible samples (e. g. Zero-insertion). One possible embodiment of the Baseband Signal Generator 606 is given by formula s(t):Zma[m+c]exp[j2rc(m+1/2) (t-NCPTS)Af ], Where the sum 2m ranges over m. In accor dance to the 3GPP speci?cation TS36.21 l, as TSII/(I 5000>< 2048) Where “x” is just multiplication. Here, Af is 15 kHZ. Here, NCP is the number of Cyclic Pre?x (CP) samples, Which can be transmitted for every symbol, as common in OFDM based systems. Also note that Ncp can be symbol-dependent. Here, t is the continuous-time variable Whose range is as 0§t§(N+NG)TS Where NI2048. Here, sequence a[m+c] is assumed to have M non-Zero elements. Here, c is just an offset, Which can be equal, for example, to ?oor(M/2). In this case, the sum 2 ranges over “m” inside the set {—?oor(M/2), —?oor(M/2)+l, . . . , ceil(M/2)—l }, Where ?oor is the knoWn “?oor” function and “ceil” is the known ceiling function. Note that “m+1/2” in the above sum performs a frequency offset of 1/2 tone, implemented in the baseband, for purpose of DC-offset mitigation of the Direct Conversion problem. Note that this is just an embodiment of the Baseband Signal Gen erator 606, and other embodiments, Which different speci?c numbers are possible. Thus, different modi?cations to the Baseband Signal Generator 606 are possible, Which don’t affect the scope of the Present Invention. Components of the Baseband Signal Generator can be implemented using the Inverse Discrete Fourier Transform (IDFT). [0040] In some embodiments of the invention, as shoWn in FIG. 6, the Scheduling Message 620 is used to con?gure the Resource Map 605, and to select the PoWer Con?guration. The Scheduling Message 620 can be communicated to the UE in the physical doWnlink control channel (PDCCH), and it contains, among other things, the selection of Which RBs should the UE utiliZe. Consequently, the Scheduling Message con?gures the set of tones Which the UE uses. HoWever, in the embodiment of the invention, the Scheduling Message 620 is also used to determine the poWer con?guration 61 0 of the UE. The PoWer Con?guration of the UE is selected from the set of at least First PoWer Con?guration 611 and Second PoWer Con?guration 612. In some embodiments, PoWer Con?gura tion of the UE can contain any of the parameters (PO, 0t, ATF[k], g[k]) as described before. Thus, in the embodiment of the invention, if the Scheduling Message 620 is indicative of the ?rst FDM band, then a First PoWer Con?guration 611 is selected, and id the Scheduling Message 620 is indicative of the second FDM band, then a Second PoWer Con?guration 612 is selected. In cases Where the Scheduling Message is not present, a default poWer con?guration can be selected from the set of at least First PoWer Con?guration and Second PoWer Con?guration. In some embodiments, the Scheduling Message 620 is derived by combining multiple doWnlink control (PDCCH) transmissions. Thus, the Scheduling Mes

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sage 620 comprises information Which is derived from doWn link control signals (PDCCH signaling or RRC signaling), and Which indicated Which FDM band should be used for transmission. In some embodiments, ?rst FDM band is PUCCH and second FDM band is PUSCH, or vice-versa. Note that Scheduling Message 620 can also narroW-doWn Which RBs speci?cally are to be used, since an FDM band can comprise multiple RBs. In some embodiments, the Schedul ing Message 620 can also con?gure (implicitly or explicitly) Whether the transform pre-coder is to be used or not, Which is also indicated in the diagram from FIG. 6. [0041] FIG. 5 is a block diagram ofa UE 520 and multiple interconnected base stations 502, 502n in the netWork of FIG. 1. As shoWn in FIG. 5, Wireless networking system 500 com prises a mobile UE device 520 in communication With a serving NodeB 502. The mobile UE device 520 may represent any of a variety of devices such as a server, a desktop com puter, a laptop computer, a cellular phone, a Personal Digital Assistant (PDA), a smart phone or other electronic devices. In some embodiments, the electronic mobile UE device 520 communicates With the NodeB 502 based on a LTE or E-UT RAN protocol. Alternatively, another communication proto col noW knoWn or later developed can be used. In some embodiments of the invention, channels PUSCH and PUCCH are on different FDM bands and are con?gured by ?rst and second poWer con?gurations, respectively. [0042] Mobile UE device 520 comprises a processor coupled to a memory and a Transceiver 522 that is controlled by the processor. Transceiver 522 includes a receiver for receiving transmissions form a serving NodeB 502 and a transmitter similar to that described With respect to FIG. 6 for transmitting to the serving NodeB. The memory stores (soft Ware) applications for execution by the processor. The appli cations could comprise any knoWn or future application use ful for individuals or organizations. As an example, such applications could be categoriZed as operating systems (OS), device drivers, databases, multimedia tools, presentation tools, Internet broWsers, e-mailers, Voice-Over-Intemet Pro tocol (VOIP) tools, ?le broWsers, ?reWalls, instant messag ing, ?nance tools, games, Word processors or other catego r1es.

[0043] Regardless of the exact nature of the applications, at least some of the applications may direct the mobile UE device 520 to transmit uplink (UL) signals on a physical uplink shared channel (PUSCH) to the NodeB (base-station) 502 periodically or continuously via its transceiver. A request for transmission resources is made via a physical uplink con trol channel (PUCCH). A scheduling grant is received from the serving NodeB via the physical doWnlink control channel (PDCCH). In some embodiments, serving NodeB 502 may provide tWo or more sets of poWer con?gurations for the UE to use during its transmission.

[0044] As shoWn in FIG. 5, NodeB 502 comprises a Pro cessor 503 coupled to a memory 504 and a transceiver 510. The memory 504 stores applications 505 for execution by the processor 503. The applications 505 could comprise any knoWn or future application useful for managing Wireless communications. At least some of the applications 505 may direct the base-station to manage transmissions to or from the user device 520. For example, scheduler application 512 is responsible for scheduling transmissions of 520. Measurer application 513 is useful for measuring FDM band-speci?c cell parameters. The operation of scheduler 512 and measurer 513 are described in more detail above.

Oct. 9, 2008

[0045] One of the applications directs NodeB 502 to derive a set of band-speci?c cell parameters. NodeB 502 sends all or a portion of these derived sets of band-speci?c cell param eters to other NodeBs 502n via a backhaul netWork 522 using communication manager 520. Communication manger 520 includes a transmitter for transmitting on the backhaul net Work and a receiver for receiving information from the back haul netWork. NodeB 502 also receives sets of band-speci?c cell parameters from other NodeBs 502n via the backhaul netWork under control of respective communication manager 520n.

[0046] Transceiver 510 is a device used to sense and trans mit radio signals. As Would be understood by one of skill in the art, the components of the scheduler 512 may involve the physical (PHY) layer and/or the Media Access Control (MAC) layer. Transceiver 510 includes a receiver for receiv ing transmissions from various UE Within range of the NodeB.

[0047] Uplink scheduler 512 executes instructions that control the operation of transceiver 510. Scheduler 512 con trols the transmission resources allocated to each UE that is being served by NodeB 502 and sends band-speci?c poWer con?gurations via the physical doWnlink control channel PDCCH.

[0048] FIG. 8 is a How diagram illustrating derivation of FDM band-speci?c cell parameters for use in the netWork of FIG. 1. At least one FDM band-speci?c cell parameter is computed 802 for at least one of a plurality of FDM bands based on information relevant to the cell being served by the NodeB. As discussed above, each FDM band may be an individual channel or may be a group of resource blocks.

[0049] Each FDM band-speci?c parameter may be com puted 802 in response to scheduling information developed by the NodeB for its served cell. This scheduling information may pertain to identities of UEs scheduled on the ?rst FDM band, indicators if UEs scheduled on ?rst FDM band belong to a class of high-interference UEs, number of UEs scheduled on ?rst FDM band, poWer assignments of UEs scheduled on ?rst FDM band, modulation of UEs scheduled on ?rst FDM band, channel coding information for UEs scheduled on ?rst FDM band, and/or schedule duration for UEs scheduled on ?rst FDM band, for example, as described in more detail above.

[0050] Each band-speci?c parameter may be derived 802 in response to channel speci?c measurements made by the NodeB serving a respective cell. In this case, the measure ments may be based on one or more of the folloWing: inter ference poWer measurement, thermal noise poWer measure ment, received signal poWer measurement, signal-to interference-poWer-ratio (SIR) measurement, signal-to interference-and-thermal-noise-poWer (SINR) measurement, rise-over thermal (RoT) measurement, throughput measurement, and cell-edge throughput measure ment, for example, as described in more detail above.

[0051] A signal from each UE is monitored by its serving cell site and also by non-serving neighbor cell sites. Depend ing on cell layout, topography, obstructing objects, etc, not every neighbor of a given serving cell site Will be able to measure signals from a particular UE. Based on the measured signal strength from a UE, both the non-serving cell sites and the serving cell site compute 802 band-speci?c cell param eters in response to transmissions from served and non-served UE.

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[0052] After computing the sets of band-speci?c cell parameters, they are transmitted 804 to other NodeB. As discussed above, typically the other NodeB are adjacent neighbors, but there may be a central or regional controller that coordinates activity of a number of NodeBs. A single NodeB may serve several cells, therefore, band-speci?c information may be derived for one cell by a NodeB, and then “transmitted” to the same NodeB for use in another cell served by the same NodeB. [0053] The neighboring cell sites communicate the sets of band-speci?c cell parameters through inter-cell communica tion netWorks. Upon receiving 806 band-speci?c cell param eters from neighboring non-serving cell sites, the serving cell site combines 806 the band-speci?c cell parameters from non-serving cell sites, together With its oWn derived band speci?c cell parameters. [0054] From this combination, the serving cell site can adjust 808 use of at least one of FDM bands in order to reduce or minimiZe interference betWeen the served cell and neigh boring cells. As described in more detail above, this adjust ment in the use of the FDM bands may involve selectively scheduling use of a particular band by a UE in the served cell to avoid interference from use of the same band by a different UE in a neighboring cell. Alternatively, this adjustment in use of the FDM bands may involve sending tWo or more band speci?c poWer commands to a particular UE so that the UE is enabled to transmit in different poWer levels, depending on the FDM band that is allocated for transmission. [0055] FIG. 9 is a How diagram illustrating use of FDM band-speci?c cell parameters in the netWork of FIG. 1. As described With respect to FIG. 8, at least one band-speci?c cell parameter is computed 802, and then transmitted 804 to neighboring cells NodeBs, additional sets of band-speci?c cell parameters are received and combined 806 With the locally computed sets and use of the FDM bands Within the cell are adjusted 808 accordingly. [0056] These adjustments in use of the FDM bands are then transmitted to and received 910 by a particular UE served by the NodeB as tWo or more sets of band-speci?c UE con?gu rations. In some embodiments, band-speci?c UE con?gura tions are band-speci?c poWer con?gurations. In either case, as described in more detail above, a particular UE Will operate 912 in a manner that is responsive to the band-speci?c con ?gurations. For example, a given UE may transmit to the NodeB on a ?rst FDM band using a ?rst band-speci?c con ?guration, and then at a later time transmit to the NodeB on a second FDM band using a second band-speci?c con?gura tion. In some embodiments, the UE utiliZes a DFT pre-coder, and When doing so, a con?guration is shared across all RBs (and thus, tones) Which are coupled to the output of the DFT pre-coder. In some embodiments, either the First FDM band or the second FDM band is used for any given time duration, Which achieves a transmission With a loW peak to average poWer ration (PAPR). In other embodiments, both the First FDM band and the Second FDM band can be used simulta neously. [0057] FIG. 10 is a block diagram ofmobile cellular phone 1000 for use in the netWork of FIG. 1. Digital baseband (DBB) unit 1002 can include a digital processing processor system (DSP) that includes embedded memory and security features. Stimulus Processing (SP) unit 1004 receives a voice data stream from handset microphone 1013a and sends a voice data stream to handset mono speaker 1013b. SP unit 1004 also receives a voice data stream from microphone

Oct. 9, 2008

1014a and sends a voice data stream to mono headset 1014b.

Usually, SP and DBB are separate ICs. In most embodiments, SP does not embed a programmable processor core, but per forms processing based on con?guration of audio paths, ?l ters, gains, etc being setup by softWare running on the DBB. In an alternate embodiment, SP processing is performed on the same processor that performs DBB processing. In another embodiment, a separate DSP or other type of processor per forms SP processing. [0058] RF transceiver 1006 includes a receiver for receiv ing a stream of coded data frames and commands from a cellular base station via antenna 1007 and a transmitter such described With respect to FIG. 6 for transmitting a stream of coded data frames to the cellular base station via antenna 1007. Transmission of the PUSCH data is performed by the transceiver using the PUSCH resources designated by the serving NodeB. In some embodiments, frequency hopping may be implied by using tWo or more bands as commanded by the serving NodeB. In this embodiment, a single transceiver can support multi-standard operation (such as EUTRA and other standards) but other embodiments may use multiple transceivers for different transmission standards. Other embodiments may have transceivers for a later developed transmission standard With appropriate con?guration. RF transceiver 1006 is connected to DBB 1002 Which provides processing of the frames of encoded data being received and transmitted by the mobile UE unite 1000.

[0059] The EUTRA de?nes SC-FDMA (via DFT-spread OFDMA) as the uplink modulation. The basic SC-FDMA DSP radio can include discrete Fourier transform (DFT), resource (i.e. tone) mapping, and IFFT (fast implementation of IDFT) to form a data stream for transmission. To receive the data stream from the received signal, the SC-FDMA radio can include DFT, resource de-mapping and IFFT. The opera tions of DFT, IFFT and resource mapping/de-mapping may be performed by instructions stored in memory 1012 and executed by DBB 1002 in response to signals received by transceiver 1006. As described in more detail above, band speci?c poWer and scheduling con?gurations canbe provided to a cell phone by the serving NodeB for use in controlling operation of the transmitter on a channel speci?c basis.

[0060] DBB unit 1002 may send or receive data to various devices connected to universal serial bus (U SB) port 1026. DBB 1002 can be connected to subscriber identity module (SIM) card 1010 and stores and retrieves information used for making calls via the cellular system. DBB 1002 can also connected to memory 1012 that augments the onboard memory and is used for various processing needs. DBB 1002 can be connected to Bluetooth baseband unit 1030 for Wire less connection to a microphone 1032a and headset 1032b for sending and receiving voice data. DBB 1002 can also be connected to display 1020 and can send information to it for interaction With a user of the mobile UE 1000 during a call process. Display 1020 may also display pictures received from the netWork, from a local camera 1026, or from other sources such as USB 1026. DBB 1002 may also send a video stream to display 1020 that is received from various sources such as the cellular netWork via RF transceiver 1006 or cam era 1026. DBB 1002 may also send a video stream to an external video display unit via encoder 1022 over composite output terminal 1024. Encoder unit 1022 can provide encod ing according to PAL/SECAM/NTSC video standards.

US 2008/0247375 A1

[0061] As used herein, the term “coupled” or “connected,” means electrically connected, Wire-line or Wireless, including Where additional elements may be in the electrical connection path. While the invention has been described With reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various other embodiments of the invention Will be apparent to persons skilled in the art upon reference to this description. While a mobile user equip ment device has been described, embodiments of the inven tion are not limited to mobile devices. Desktop equipment and other stationary equipment being served by a cellular netWork Will also participate in the channel-speci?c poWer control methods described herein. It is therefore contem plated that the appended claims Will cover most such modi ?cations of the embodiments as fall Within the true scope and spirit of the invention [0062] In some embodiments, computing FDM band-spe ci?c cell parameters comprises performing described set of measurements for at least one FDM band (performing FDM band-speci?c measurements), folloWed by processing said measurements. This processing can include a simple pass through, quantization, sorting, classi?cation, aggregation, table look-ups, or any other form of digital processing. In some embodiments, computing FDM band-speci?c cell parameters is performed using information produced by the NodeB scheduler. The information produced by the NodeB scheduler can comprise identities of scheduled UEs, identi ties of resource blocks that said UEs are scheduled on, iden tities of sub-frames that UEs are scheduled on, modulation assignment for said UEs and channel coding assignment for said UEs. Consequently, in some embodiments, term per forming UE scheduling decisions comprises deciding on the identities of scheduled UEs, identities of resource blocks that said UEs are scheduled on, identities of sub-frames that UEs are scheduled on, modulation assignment for said UEs and channel coding assignment for said UEs, and possible other decisions. In some embodiments, scheduling decisions are processed to compute the value of the FDM band-speci?c parameter. In some embodiments, this processing can include identi?cation if a scheduled UE belongs to a pre-de?ned set (or class) of UE, such as a cell-edge UE, Which can create high interference to adjacent cells. In some embodiments, elements of scheduling decisions can simply be transmitted to the second NodeB Without any speci?c processing. Some embodiments of the invention require identifying a group of FDM bands for Which the computed band-speci?c cell parameter value belongs to a pre-determined set of values. This can be performed by comparing each computed value of the FDM band-speci?c parameter against a pre-de?ned set of values. If the computed value belongs to the said pre-de?ned set of values, the particular FDM band belongs to the group. A simple example is threshold-ing of FDM band-speci?c parameters (for example interference estimates), Where a group of FDM bands comprises those FDM bands Where parameter (e.g. interference estimate) exceeds the threshold. Furthermore, note that, in some embodiments, the threshold can be speci?c to each FDM band (i.e. each FDM band can have a different threshold). Some embodiments of the inven tion mention transmit poWer adjustments. In some embodi ments, a transmit poWer adjustment is a differential correc tion With respect to previous transmit poWer, such as an increase or reduction by x dB. In other embodiments, a trans mit poWer adjustment can be a complete re-con?guration of transmit poWer settings.

Oct. 9, 2008

What is claimed: 1. A method for operating a cellular netWork, Where said

cellular netWork uses a plurality of frequency division multi plexing (FDM) bands for Wireless communication from at least one user equipment (UE) to at least one base station (NodeB), comprising:

computing at least one band-speci?c cell parameter for at least one FDM band of the plurality of FDM bands; and

transmitting said band-speci?c cell parameter from a ?rst NodeB serving a ?rst cell to a second NodeB serving a second cell.

2. Method of claim 1, further comprising: identifying a group of FDM bands for Which the computed

band-speci?c cell parameter value belongs to a pre determined set of values; and

Wherein transmitting said band-speci?c cell parameter comprises transmitting information re?ective of the identi?ed group of FDM bands.

3. The method of claim 1, Wherein ?rst NodeB and second NodeB are the same.

4. The method of claim 1, Wherein computing a band speci?c cell parameter for a ?rst FDM band comprises:

performing UE scheduling decisions at the ?rst NodeB for the ?rst cell; and

processing said UE scheduling decisions at the ?rst NodeB to compute the value for the band-speci?c cell param eter.

5. The method of claim 4, Wherein said band-speci?c cell parameter for the ?rst FDM band is selected from a group consisting of: identities of UEs scheduled on the ?rst FDM band, indicators if UEs scheduled on ?rst FDM band belong to a class of high-interference UEs, number of UEs scheduled on ?rst FDM band, poWer con?gurations of UEs scheduled on ?rst FDM band, modulation of UEs scheduled on ?rst FDM band, channel coding information for UEs scheduled on ?rst FDM band, and schedule duration for UEs scheduled on ?rst FDM band.

6. The method of claim 1, Wherein computing band-spe ci?c cell parameter for a ?rst FDM band comprises:

performing band-speci?c measurements for at least the ?rst FDM band at the ?rst NodeB for the ?rst cell; and

processing said band-speci?c measurements at the ?rst NodeB to compute a value for said band-speci?c cell parameter.

7. The method of claim 1, Where said cellular netWork uses a ?rst FDM band for multiplexing physical uplink shared channel (PUSCH) UEs and a second FDM band for multi plexing physical uplink control channel (PUCCH) UEs.

8. The method of claim 7, Where said ?rst FDM band comprises a plurality of FDM bands.

9. The method of claim 6, Wherein said band-speci?c mea surement is made using received samples from at least the ?rst FDM band, and Wherein said band-speci?c measurement is selected from a group consisting of: interference poWer measurement, thermal noise poWer measurement, received signal poWer measurement, signal-to-interference-poWer-ra tio (SIR) measurement, signal-to-interference-and-thermal noise-poWer (SINR) measurement, rise-over thermal (RoT) measurement, throughput measurement, and cell-edge throughput measurement.

10. The method of claim 9, Wherein said band-speci?c measurement is quantiZed to produce said band-speci?c cell parameter.

US 2008/0247375 A1

11. The method of claim 9, wherein transmission occurs Whenever said band-speci?c parameter value belongs to a pre-determined set of values.

12. The method of claim 1, Wherein each said FDM band is an integral multiple of 180 kHZ.

13. The method of claim 1, Wherein said Wireless commu nication betWeen UEs and NodeBs comprises a DFT pre coder operation.

14. The method of claim 1, further comprising: receiving another band-speci?c cell parameter from said

second NodeB; and adjusting use of at least said one FDM band from the

plurality of FDM bands, in response to said received band-speci?c cell parameter.

15. The method of claim 14, Wherein adjusting use of at least one said FDM band comprises scheduling a UE trans mission on the FDM band in the ?rst cell to avoid interference from use of the ?rst FDM band by a different UE in the second cell.

16. The method of claim 14, Wherein adjusting use of at least said one FDM band comprises sending at least one band-speci?c poWer con?guration message to a UE served by the ?rst NodeB.

17. The method of claim 16, further comprising: receiving at the UE a ?rst poWer con?guration message for

a ?rst FDM band; receiving at the UE a second poWer con?guration message

for a second FDM band; receiving at the UE a scheduling message indicative of a

selection of an FDM band from a plurality of FDM bands that includes a ?rst FDM band and a second FDM

band; transmitting by the UE on the ?rst FDM band With the ?rst poWer con?guration if said scheduling message indi cated a selection of a ?rst FDM band; and

transmitting by the UE on the second FDM band With the second poWer con?guration if said scheduling message indi cated a selection of the second FDM band.

18. A base station (NodeB) apparatus for use in a cellular netWork, Wherein said cellular netWork uses a plurality of frequency division multiplexing (FDM) bands for Wireless communication from user equipment (UE) to the NodeB, comprising:

a processor connected to a memory circuit for holding instructions for execution by the processor, Wherein the processor is operable to compute at least one band speci?c cell parameter; and

a transmitter controllably coupled to the processor, the transmitter having an output for coupling to an inter NodeB backhaul netWork, the transmitter being oper able to transmit the computed band-speci?c cell param eter via the inter-NodeB backhaul netWork.

19. The NodeB of claim 18, further comprising: a receiver coupled to a processor, the receiver having an

input for coupling to the inter-NodeB backhaul netWork, Wherein the receiver is operable to receive at least one band-speci?c cell parameter via the inter-NodeB back haul netWork.

20. A method for operating a user equipment (UE) in a cellular Wireless netWork, Where said cellular netWork uses a

Oct. 9, 2008

plurality of frequency division multiplexing (FDM) bands for Wireless communication from UEs to a base station (N odeB), comprising:

receiving a ?rst poWer con?guration message for a ?rst FDM band;

receiving a second poWer con?guration message for a sec ond FDM band;

receiving a scheduling message indicative of a selection of an FDM band from a plurality of FDM bands including the ?rst FDM band and the second FDM band;

transmitting on the ?rst FDM band With the ?rst poWer con?guration if said scheduling message indicated a selection of the ?rst FDM band; and

transmitting on the second FDM band With the second poWer con?guration if said scheduling message indicated a selection of the second FDM band.

21. The method of claim 20, Where said cellular netWork uses the ?rst FDM band for multiplexing physical uplink shared channel (PUSCH) UEs and a second FDM band for multiplexing physical uplink control channel (PUCCH) UEs.

22. The method of claim 20, further comprising: transmitting on the ?rst FDM at a previous transmit poWer;

and Wherein said ?rst poWer con?guration message includes a

transmit poWer adjustments in reference to the previous transmit poWer on the ?rst FDM band.

23. The method of claim 22, further comprising: transmitting on the second FDM at a previous transmit

poWer; and Wherein said second poWer con?guration message

includes a transmit poWer adjustments in reference to previous transmit poWer on the second FDM band.

24. The method of claim 20, further comprising: transmitting on the ?rst FDM at a previous transmit poWer

spectral density; and Wherein said ?rst poWer con?guration message includes

transmit poWer spectral density adjustments in reference to the previous transmit poWer spectral density on the ?rst FDM band.

25. A user equipment (UE) for use in a cellular Wireless netWork, Where said cellular netWork uses a plurality of fre quency division multiplexing (FDM) bands for Wireless com munication from UEs to a base station (NodeB), comprising:

a processor connected to a memory circuit for holding instructions for execution by the processor;

a receiver coupled to the processor being operable to receive from a serving NodeB and to provide to the processor a ?rst poWer con?guration message for a ?rst FDM band, a second poWer con?guration message for a second FDM band, and a scheduling message indicative of a selection of an FDM band from a plurality of FDM bands including the ?rst FDM band and the second FDM band;

a transmitter controllably coupled to the processor oper able to transmit to the serving NodeB; and

Wherein the processor is operable to cause the transmitter to transmit on the ?rst FDM band With the ?rst poWer con?gu ration if said scheduling message indicated a selection of the ?rst FDM band, and to transmit on the second FDM band With the second poWer con?guration if said scheduling message indicated a selection of the second FDM band.

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